Stumpy Evo - 170/160
Stumpjumper Evo Alloy - 170/160 Cascade + WRP Mullet
After multiple seasons of testing and tuning I thought it was time to share my findings. I iterated over 3 build configurations testing this bike on everything from rolling XC to Bike Parks… This Stumpy Evo has become one of my favorite builds 170/160 Stumpjumper Evo Alloy S3
Rider Profile
Height: 5’7”
Weight: 185 lbs
Primary terrain: PNW blue & black trails
Bike Parks: Snoqualmie & Stevens Pass
Where it began…
2021-2024 Specialized Stumpjumper Evo Alloy - 160/150 stock build
Berm Party Build:
Stumpjumper Evo Alloy S3
(170/160 MX)
Frame: 2024 Specialized Stumpjumper Evo Alloy – S3
Fork: FOX 38 – 170mm – 44mm offset (GRIP)
Shock: FOX Float X
Geo Setting:
Long chainstay (441mm)
Neutral (0°) headset
Linkage: Cascade Link + WRP Link
Drivetrain: SRAM GX 12-speed, 170mm crank
Bars: Deity Black Label +38mm rise
Stem: FUNN Equalizer - 35mm length
Stack Spacers: 30mm
Effective Stack: 708mm (from stock 630mm)
Wheel & Tire Configurations
Enduro Setup (Bike Park)
Wheels: Hunt Enduro Wide MX
Front: Butcher 29 x 2.6 T9 Grid Gravity + Tannus Insert
Rear: Butcher 27.5 x 2.3 T7 Grid Trail + Tannus Insert
Trail Setup
Wheels: Hunt Trail Wide V2 MX
Front: Butcher 29 x 2.6 T7 Grid Trail + Tannus Insert
Rear: Ground Control 27.5 x 2.3 T7 Grid Trail + Tannus Insert
Configurations Tested
Full 29 – 170mm FOX 38 with Stock Linkage
Climbing: 5/10
Bike Park: 6/10
Traits: Planted, long and difficult to setup the rear end.
The wheelbase added stability, but as a 5’7” rider coming from a shorter wheelbase 27.5 platform, the bike felt long in tight corners and technical climbs.
Full 29 – 170mm + Cascade Link
Climbing: 7/10
Bike Park: 7/10
Traits: Planted, Improved Pedaling, Massive Pop & Easier shock adjustments
The Cascade Link improved bottom-out on big hits and the increased progression gave me a much better pedal platform as I was able to increase the shock pressure by 35 psi and still retain 25% sag. The wheelbase length remained noticeable in tighter terrain.
MX (29/27.5) – Cascade + WRP Link
Climbing: 8.5/10
Bike Park: 9/10
Traits: Playful, poppy, responsive
This is the sweet spot.
The mullet configuration transformed the bike. It became easier to corner and more forgiving on technical climbs. With the WRP link, the bike regained playfulness on mellow terrain while still holding its composure at speed.
This is the most enjoyable “one-bike quiver” setup I’ve ridden.
I don’t change suspension settings between trail and park days. I simply swap wheels and tires.
Favorite Tires
XC riding:
Maxxis Dissector (2025) 2.4 EXO Front / Forekaster 2.4 EXO+ Rear
Climbing Effort: 9/10
Cornering: 8.5/10
Climbing Wet rocks and roots: 3/10
Trail riding:
Kryptotal 2.4 with Trail Casing Front / Rear
Climbing Effort: 8/10
Cornering: 8.5/10
Climbing Wet rocks and roots: 9/10
Bike Park - I am torn between:
Butcher T9 2.6 front / Butcher 2.3 T7 rear (Discontinued)
Climbing: 7/10
Cornering: 9.5/10
Climbing Wet rocks and roots: 9/10
Assegai MaxGrip Exo+ Front / DHR II DD Rear
Climbing Effort: 5/10
Cornering: 10/10
Climbing Wet rocks and roots: 10/10
Who Is the Evo Alloy with Cascade Link For?
Riders that can say yes to the following…
Weigh under 210lbs / 95kg
Enjoy experimenting with geometry
Want a “bike lab” platform
Ride mixed terrain and love a poppy bike
Berm Party’s Evo Alloy 170/160 has proven to be incredibly capable and extremely fun at bike parks and on technical trails. You don’t need to ride Mach Chicken to have fun but I definitely hunt for more chunky lines when riding this 170/160 Evo Alloy.
Who It’s Not For
If you weigh over 200 lbs, I would consider another platform.
The asymmetric frame design increases shear load on the rear shock. I know multiple riders around 220 lbs who have blown shocks on this frame. The leverage curve and side loading can limit heavy rider tuning options — especially with the Cascade Link.
If you’re heavier and want a playful bike, I’d look at something like a Transition Patrol or Rock Mountain Altitude setup as a 29/27.5 bike.
Cascade Link – Yes or No?
Some reviewers say it’s unnecessary.
Berm Party take:
If you you can say yes to any of the following:
More progression
Increased pop
Better bottom-out control
Easier suspension setup
Then the cascade is a serious improvement. Riders at my Demo & Tune event were underwhelmed by the bike before upgrading.
However, heavier riders may need to run very high air pressures. On this frame, that can increase shearing forces and stress on the shock.
I’ve run Cascade Links on other bikes (like my 2019 Kona Process 153), and in some cases it reduced playfulness on mellow terrain. On the Evo, paired with the WRP link, it works beautifully. I hosted a Berm Party Demo & Tune event and this configuration received praise from everyone that took a lap.
Climbing Reality
Compared to four-bar platforms, climbing is average in stock form.
However, the cascade link and 27.5 wheel helped reduce pedal bob and improve maneuverability on climbs significantly. If you are looking to change up the ride experience I recommend the following upgrades:
Cascade Link
WRP Link
27.5 rear wheel
That combination moves this long travel enduro machine into quiver killer territory.
Warning: Chainstay Wear…
I noticed premature chainstay damage on my frame as well as a friend's frame. To resolve this I added a 3mm bottom bracket spacer to shift the chainring slightly outward. It may have been an installation error — or it may be an issue with chain line tolerance caused by an over sight in frame design. In any case the issue seems to have gone away with this modification.
What Size Should You Buy?
Height and terrain matter more than most people think.
I’ll be testing S2, S3, and S4 sizes with riders from 5’0” to 6’2”. Geometry differences can strongly influence whether a rider prefers full 29 or MX.
What I Love
Adjustable geometry — Chainstay and Headtube Angle
Playful yet ready to devour chunky trail
Butcher 2.6 T9 / 2.3 T7 for bike park (Pre-2025 Discontinued)
Kryptotal 2.4 tires 29/27.5 for Trail Riding
What I’d Change
FOX GRIP damper lacks mid-stroke support
I’ll be testing MRP damper options, DSD Runt, and volume tokens
Asymmetric frame limits coil compatibility (Fox DHX only)
Final Verdict
If you want a single bike that can:
Ride tech
Pop off everything
Handle park days
Teach you about geometry
Our custom built Berm Party 170/160 Evo Alloy MX is a excellent build pathway especially for riders under 210 lbs.
